The 55-year-old daily was a platform for people of all shades of opinion to share their political views, and for columnists to hold "sparring matches on paper", they said.

Ming Pao editors rarely altered their writing, the columnists said. "[It] respects the opinions and stances of the contributors," they said in a statement.

The petitioners requested that management ensure continued editorial impartiality despite the saga.

They also asked the management to promise not to retaliate against employees who expressed concerns over Lau's removal, and to meet all staff to explain the matter.

On Monday, Lau informed his colleagues he was slated to manage the Ming Pao Group's electronic books and teaching materials division and would be replaced by a Malaysian journalist.

The next day, more than 90 per cent of Ming Pao's 270-strong editorial staff signed a petition demanding an answer from management.

They were joined by about 270 former journalists of the paper. Petitioners were worried that it would be just the start of an editorial reshuffle, potentially linked to the mainland investments of the newspaper's Malaysian owner, Tiong Hiew King.

This article appeared in the South China Morning Post print edition as: